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Capillary zone electrophoresis/mass spectrometry of 5‐aminolaevulinic acid and porphobilinogen
Author(s) -
Lord Gwyn A.,
Luo Jin Li,
Lim Chang Kee
Publication year - 2000
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/(sici)1097-0231(20000315)14:5<314::aid-rcm846>3.0.co;2-0
Subject(s) - chemistry , chromatography , capillary electrophoresis , mass spectrometry , formic acid , electrospray ionization , electrospray , analytical chemistry (journal) , protonation , aqueous solution , ion , detection limit , ammonium acetate , high performance liquid chromatography , organic chemistry
A capillary zone electrophoresis/electrospray ionisation mass spectrometry (CZE/ESI‐MS) method has been developed for the separation and detection of 5‐aminolaevulinic acid (ALA) and porphobilinogen (PBG). Capillaries were 70 cm long with an inner diameter of 75 µm and outer diameter of 375 µm. The buffer used was aqueous ammonium acetate (50mM, pH 5.2) with a co‐axial ‘make‐up’ flow of methanol/aqueous 0.1% formic acid (1:1 v/v) at a flowrate of 6 µL/min. A voltage of 20 kV was used for CZE and an ESI voltage of 3.5 kV. Full scan data was acquired over the range m/z 100–500 in positive ion mode, from which selected ion electropherograms were extracted; at m/z 132 for the protonated molecular ion of ALA and m/z 210 for the methylenepyrrolenine fragment ion of PBG. The protonated molecular ion of PBG, m/z 227, was found to be too facile to monitor, easily losing ammonia in the electrospray source and better sensitivity was achieved by monitoring the resulting fragment ion. The detection limits were circa 100 attomoles of ALA and 10 attomoles of PBG at a signal‐to‐noise ratio (S/N) better than 10, providing sufficient sensitivity for clinical use and offering advantages over existing techniques. Copyright © 2000 John Wiley & Sons, Ltd.